Functional scores are used to clinically assess total hip arthroplasty (THA) and for comparative purposes in the orthopaedic literature. Previous research has highlighted patient age, gender and underlying diagnosis as potential sources of bias but comorbidity has not been considered. The Functional Comorbidity Index (FCI) is a published epidemiological tool which correlates disease with associated physical function deficit. It scores 18 conditions: one point for each, total score 0–18. We analysed 41 fully cemented primary THAs in patients ≤55 years at time of surgery with a minimum 10 years follow up. Past medical history was collected via thorough case note review. Patients were assessed using the SF-12 questionnaire, Harris Hip and WOMAC indexes. The study population consisted of 29 patients: 12 women, 17 men. Mean age: 45 years (range 22–53). All patients received cemented polished Corin TaperFit stem with polyethylene Ogee cup. Mean follow up 13.4 years (range 10.2–17.7). FCI scores ranged 0–3 (12 hips=0; 19 hips=1, 5 hips=2, 5 hips=4). A Pearson's product-moment correlation coefficient was calculated to assess the relationship between co-morbidity and hip function score using all three indexes.
Mean by FCI subgroup: 0=91, 1=96, 2=76.8, 3=68.6 (r=−0.407)
Mean by FCI subgroup: 0=94.7; 1=88.2, 2=63.5, 3=54.6 (r= −0.813)
Mean by FCI subgroup: 0=94.4, 1=91.72, 2=48.8, 3=37.4 (r=−0.812)Introduction
Method & Results
Revision hip surgery is reportedly rising inexorably yet not all units report this phenomenon. The outcome of 1143 consecutive Corin TaperFit primary hip arthroplasties (957 patients) performed between 1995 and 2010 is presented. The implants were cemented under pressurisation and combined the TaperFit stem with Ogee flanged cups. Data was gathered from local arthroplasty database and case note review of revised joints. 13 hips have been revised (1.1%). Cumulative prosthesis survival is 0.99 +/− 0.0. Two femoral stems were revised (0.2%); one at 6 months for sepsis, one at 14 days after dislodgment during reduction of dislocation. No revisions were undertaken for aseptic loosening of the stem or cup, nor for thigh pain. 32 patients (32 hips) ≥15 year follow up, 13 survive today and none have been revised (0%). Of the 471 with ≥10 year follow up, 38 were aged ≤50 at time of surgery and 1/38 has been revised to date (PLAD for dislocation). The strong population stability in this region, supported by independent investigation by Scottish Arthroplasty Project, endorses the accuracy of the data quoted. The low incidence of revision in this cohort, and absence of revision for aseptic loosening (mean follow up 8.03 years +/− SD 3.94; range 18 months to 16yrs 2 months), substantially supports the longevity and use of cemented, double-taper, polished, collarless femoral stems in combination with cemented polyethylene cups in primary hip arthroplasty in all patient age groups.
